#### Harry_the_cat

##### Elite Member

- Joined
- Mar 16, 2016

- Messages
- 3,475

I think everyone missed it, but I think, on your first line of working, you mean \(\displaystyle cos 30^o=\frac{\sqrt{3}}{2}\)View attachment 34097

I have used a calculator for this and got 192. Question how do I find these without a calculator is there a method that anyone knows?

[math]tan(30°) = \frac{ \sqrt{3}}{2}[/math]0

[math]tan(60^{\circ}) = \sqrt{3}[/math][math]12 × \frac{\sqrt{3}}{2} +2 × \sqrt{3} = 8\sqrt{3}[/math]